Body Composition
What are healthy ranges of body fat for males and females?
12-18% for males and 18-23% for females. Note: athletes may have different % ranges depending on their activity, such as endurance athletes vs. football players. There may also be specific formulas based on gender, age, sport, etc. It is recommended that no individual be below 5% body fat.
What are the standard skin fold sites?
Abdominal, medial calf, supra iliac, biceps, midaxillary, thigh, chest/pectoral, sub scapular, triceps (subscapular and triceps are the most commonly used sites)
What is the skin fold measurement procedure?
All measurements are taken on the right side of the body. Take multiple measurements at each site to ensure accuracy and retest if the difference is greater than 1-2 mm. Skin fold calipers should be positioned 1 cm away from the examiner's fingers when pinching the side, positioned perpendicular to the skin fold, and centered between the base and top of the fold. Wait 1-2 seconds before reading the caliper. Maintain pinching of the site during reading of the caliper.
What are two examples of densitometry?
Hydrostatic weighing and plethysmography
What are methods for testing the percentage of body fat?
Hydrostatic weight, plethysmography, skin fold measurements, body mass index, and bioelectrical impedance analysis.
BMI classification system
Less than 18.5: underweight 20-24.9: desirable 25-29.9: overweight 30-34.9: class 1 obesity 35-39.9: class 2 obesity Greater than 40: class 3 obesity
What is a limitation of BMI?
The formula does not measure proportional composition of the body or percentage of fat. The standard error with estimating percent body fat using BMI is about 5%.
What is the BIA protocol?
The patient should abstain from eating or drinking within 4 hours prior to testing. The patient should abstain from vigorous physical activity within 12 hours prior to testing. The patient should urinate within 30 minutes prior to testing. The patient should avoid alcohol consumption for 48 hours prior to testing. The patient should avoid excessive water intake prior to testing.
What is body composition?
The relative percentage of body weight that is comprised of fat and fat-free tissue.
What are limitations of the bioelectrical impedance analysis (BIA)?
The requisite for the subjects to be properly hydrated as well as following all guidelines for the testing protocol.
What are some limitations of hydrostatic weighing?
There is a need to account for residual lung volume during submersion and evaluating patients that must tolerate water submersion during the testing. The standard error is 2 to 2.5%.
What are some limitations to the skin fold measurement for determining body fat?
There is a requisite of an experienced examiner as well as variance from he standards based on gender, age, and ethnicity. Accuracy of the measurement is within +/- 3% with appropriate technique and equipment.
What is body mass index (BMI)?
This formula is designed to assess risk potential for obesity-related health issues by calculating an estimated percentage of body fat. The formula divides body weight in kg by height in meters squared (kg/m^2). There is evidence that an increase in BMI is associated with an increase in mortality rate secondary to heart disease, diabetes, and cancer.
What type of measurement is the skin fold measurement?
This is a form of anthropometry
What is hydrostatic weighing?
This method calculates the density of the body by immersing a person in water and measuring the amount of water that becomes displaced. The percentage of body fat is then determined by calculating the measured amount of water displaced in an equation based n Archimedes' principle. This method is the most widely used laboratory procedure to determine body density.
What is plethysmography?
This method calculates the density of the body by utilizing the amount of air displacement during testing within a specialized closed chamber. The change in pressure within the chamber is measured and converted to the percentage of body fat using a standardized equation.
What is the skin fold measurement?
This method determines the overall percentage of body fat through the measurement of nine standardized sites. The correlation relies on the theory that the amount of subcutaneous fat is proportional to the total fat in the body.
What is the bioelectrical impedance analysis (BIA)?
This method of assessing body composition uses a small electrical current and measures the resistance or opposition to the current flow. This technique is based on the principle that resistance to electrical current is inversely related to the composition of water within the body. The formula of height^2/resistance is used for the general population while population-specific equations are also available. The standard error compares to the accuracy of skin fold measurements at approximately +/- 3%.
